Grafted fluoropolymer powders and method of making thereof

Compounds containing polar functional entities can be grafted onto the surface of fluoropolymer powders to obtain grafted fluoropolymer powders having modified surface characteristics but without modifying the bulk of the polymer in the particle. The grafted fluoropolymer powder is effective in such uses as an adhesive to join dissimilar materials.

Skip to:  ·  Claims  ·  References Cited  · Patent History  ·  Patent History

Claims

1. A process for grafting a grafting compound onto the surface of a fluoropolymer powder, comprising exposing said powder to a source of ionizing radiation without swelling said powder in the presence of an ethylenically unsaturated compound present only at the surface of said powder.

2. The process of claim 1 wherein said ethylenically unsaturated compound contains polar functional groups.

3. The process of claim 1 wherein said grafting compound and said fluoropolymer powder are contained in a closed container transparent to said ionizing radiation during said exposure.

4. Process for bonding fluoropolymer to another material, comprising bringing said fluoropolymer and said material together, in contact with one another, said fluoropolymer being either in the form of powder or melt mixture thereof, said powder having a compound grafted only to the surface thereof, either the grafted compound portion of said powder being compatible with said material or the fluoropolymer portion of said powder being compatible with said material, and heating the resultant assemblage of said material and said powder or melt mixture thereof to cause said material and said fluoropolymer to bond together.

5. The process of claim 4 wherein said heating is done prior to bringing said powder or melt mixture thereof and said material together.

6. The process of claim 4 wherein an additional material is present in contact with said powder or melt mixture thereof, either the grafted compound portion of said powder being compatible with said additional material or the fluoropolymer portion of said powder being compatible with said additional material, said heating causing said another material and said additional material to be bonded together by said powder or melt mixture thereof.

7. The process of claim 6 wherein said additional material is brought into contact with said powder or melt mixture thereof prior to said heating of said resultant assemblage or subsequent to said heating of said resultant assemblage.

8. The process of claim 6 wherein said materials to be bonded together are matrix material and filler material dispersed therein, and said powder is present at the interface between said matrix material and said filler material.

9. The product of the process of claim 8.

10. The process of claim 4 wherein said heated assemblage is forced together to assist formation of said bond.

11. A laminate prepared by the process of claim 4 comprising grafted fluoropolymer powder, either fused or melt mixed, bonded to another material, either the grafted compound portion of said powder being compatible with said material or the fluoropolymer portion of said powder being compatible with said material or the fluoropolymer portion of said powder being compatible with said material.

12. The laminate of claim 11 wherein an additional material is bonded to said fused or melt mixed powder, either the grafted compound portion of said powder being compatible with said additional material or the fluoropolymer portion of said powder being compatible with said additional material.

13. The laminate of claim 12 wherein said another material and said additional material are different materials.

14. The laminate of claim 13 wherein at least one of said materials is fluoropolymer.

15. The laminate of claim 14 wherein one of said materials is fluoropolymer and the other of said materials is other than fluoropolymer.

16. The laminate of claim 15 wherein said fluoropolymer is ETFE copolymer, said additional material comprises thermoplastic polyester elastomer, and the base fluoropolymer of said grafted fluoropolymer powder is ETFE copolymer either the same as or different from said fluoropolymer.

17. The laminate of claim 16 wherein said additional material includes amine catalyst.

18. The laminate of claim 12 having tubular configuration.

19. The tubular laminate of claim 18 as a fuel hose, heat exchanger tubing, or injection/hydraulic control hose.

Referenced Cited
U.S. Patent Documents
3716391 February 1973 Hosoda et al.
4151225 April 24, 1979 Buning
4158678 June 19, 1979 Tatemoto et al.
4278777 July 14, 1981 Jakabhazy et al.
4472557 September 18, 1984 Kawashima et al.
4506035 March 19, 1985 Barnett et al.
4661383 April 28, 1987 Elsenbaumer et al.
4910258 March 20, 1990 Inoue et al.
Patent History
Patent number: 5756199
Type: Grant
Filed: Aug 22, 1996
Date of Patent: May 26, 1998
Assignee: E. I. du Pont de Nemours and Company (Wilmington, DE)
Inventors: Dewey Lynn Kerbow (Vienna, WV), Hermann Jenewein (Geneva)
Primary Examiner: H. Thi Le
Application Number: 8/701,412